The traffic sign you mentioned, the Tourist Information Board, is used to indicate the location of tourist information services. This sign is typically blue and features a white letter "i" (for "information") in a square shape.

According to German traffic laws, this sign directs drivers to nearby facilities where they can obtain information about local attractions, accommodations, events, and other points of interest in the area. It is particularly useful in urban areas and near popular tourist destinations to enhance the travel experience for visitors.

If you have any specific questions about this sign or other traffic rules, feel free to ask!